66 THE SKIN. 



body, nor with the tactile sensibility which renders the skin 

 so useful and so safe a shield to the delicate structures it 

 clothes. 



The skin is, therefore, divided into two parts its outer 

 covering, scarf skin, cuticle or epidermis, and its vascular, 

 sensitive, and secreting portion, the true skin, cutis vera or 

 dermis. Connected with the skin are certain accessory tex- 

 tures or appendages, viz., hair, wool, horns, nails, claws, 

 hoofs, and feathers. 



The cuticle or epidermis is that layer of tissue which may 

 be obtained from any skin by macerating it. If a blister is 

 applied, the cuticle is raised from the true skin, and in 

 various diseases, such as epizootic aphtha, we notice that the 

 lymph raises the cuticle from the true skin wherever the 

 eruption occurs. This cuticle is composed of layers of cells 

 which, when recently formed, are round, nucleated, elongated, 

 or pressed into polygonal shapes. The deepest layers of cuti- 

 cular cells are the softest, and the superficial ones are flattened, 

 hard, horny, and translucent. They are very closely packed, 

 and adhere firmly together, until, by progressive addition of 

 scales in the deeper layers, the superficial ones become use- 

 less, get detached, and thrown off in the shape of dandruff, 

 or the white dusty powder which the groom obtains in such 

 quantities in dressing a horse. The cells undergo no further 

 change, from their first formation to the time they are shed, 

 than drying, and they imbibe water and regain their opacity 

 very readily. This is seen if the hand is dipped in water 

 for any length of time. 



Prom the deeper layers of cuticular cells being much 

 softer than the superficial, the cuticle has been divided into 

 two portions, the deeper of which, owing also to its per- 

 forated aspect, wherever the papillae of the skin pierce it, 

 has been called rete mucosum. It is in this deep layer that 



